Predictive accuracy and usefulness of calibration of the ESC SCORE in Switzerland

Background Prevention of cardiovascular disease (CVD) at the individual level should rely on the assessment of absolute risk using population-specific risk tables. Objective To compare the predictive accuracy of the original and the calibrated SCORE functions regarding 10-year cardiovascular risk in Switzerland. Design Cross-sectional, population-based study (5773 participants aged 35-74 years). Methods The SCORE equation for low-risk countries was calibrated based on the Swiss CVD mortality rates and on the CVD risk factor levels from the study sample. The predicted number of CVD deaths after a 10-year period was computed from the original and the calibrated equations and from the observed cardiovascular mortality for 2003. Results According to the original and calibrated functions, 16.3 and 15.8% of men and 8.2 and 8.9% of women, respectively, had a 10-year CVD risk !! 5%. Concordance correlation coefficient between the two functions was 0.951 for men and 0.948 for women, both P < 0.001. Both risk functions adequately predicted the 10-year cumulative number of CVD deaths: in men, 71 (original) and 74 (calibrated) deaths for 73 deaths when using the CVD mortality rates; in women, 44 (original), 45 (calibrated) and 45 (CVD mortality rates), respectively. Compared to the original function, the calibrated function classified more women and fewer men at high-risk. Moreover, the calibrated function gave better risk estimates among participants aged over 65 years. Conclusion The original SCORE function adequately predicts CVD death in Switzerland, particularly for individuals aged less than 65 years. The calibrated function provides more reliable estimates for older individuals. Eur J Cardiovasc Prev Rehabil 15:402-408 (c) 2008 The European Society of Cardiology